1. Field of the Invention
The present invention is generally related to a lubrication system for a marine engine and, more particularly, to an oil pan and windage tray for a marine engine that is tilted to lower its overall height.
2. Description of the Related Art
Many different types of marine propulsion systems are known to those skilled in the art. One type of sterndrive propulsion system is known which incorporates a tilted in-line engine which lowers the profile of the engine and facilitates its use in certain types of marine vessels, such as bass boats, which heretofore were not amenable to the use of sterndrive propulsion systems.
U.S. Pat. No. 4,519,348, which issued to Hamilton on May 28, 1985, describes an oil pan and windage tray for high performance engines which reduce friction loss by separating the oil collection volume of the pan from rotating engine components. A skimmer integral with the tray skims oil from rotating parts and channels oil thrown from the rotating parts into a side pouch of the pan for delivery to the pan collection volume. The skimmer and tray mount to the engine separately from the pan. An alternate embodiment of a dry sump pan has a removable partition between a side pouch and the rotating parts and a skimmer separate from the pan.
U.S. Pat. No. 6,019,071, which issued to Maciejka on Feb. 1, 2000, describes an engine windage tray. The windage tray is positioned between the crankshaft and the oil pan. It includes a passage having an inlet port receiving the pressurized oil and a first outlet port directing a first stream of the pressurized oil at the piston. In a preferred embodiment, the passage further includes a second outlet port directing a second stream of pressurized oil at the piston.
U.S. Pat. No. 6,530,354, which issued to Bishop et al. on Mar. 11, 2003, describes an oil pan with vertical baffles. The oil pan is intended for use with an engine having a crankshaft and includes a pan body adapted to be disposed beneath the crankshaft for receiving oil that is exhausted from the engine. The oil pan further includes a vertically extending baffle attached to the pan body.
U.S. Pat. No. 6,874,460, which issued to Duwel on Apr. 5, 2005, describes an integrated oil pan and windage tray. The tray is adapted for installation between the engine block and the oil pan and the tray has a body with a peripheral flange extending about the periphery of the body and at least one deflector portion extending away from the body to a location spaced away from the peripheral flange.
U.S. Pat. No. 7,014,519, which issued to Batten et al. on Mar. 21, 2006, discloses a marine propulsion system with a tilted in-line engine. The engine is disposed at a tilted angle relative to a vertical plane in order to reduce the maximum height requirement space of an engine compartment of a marine vessel. The crankshaft axis of the in-line engine can be located on a vertical vessel symmetry plane or can be offset from it. The crankshaft of the in-line engine can be disposed parallel to the vessel symmetry plane, within the vessel symmetry plane, or perpendicular to the vessel symmetry plane.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
When a marine engine is tilted, as disclosed in U.S. Pat. No. 7,014,519, the physical relationships between the crankshaft of the engine and the liquid oil within the oil sump portion of an oil pan are changed. These physical relationships can result in certain disadvantageous conditions, such as aeration of the liquid oil within the oil pan. If a significant amount of air is suspended within the liquid oil in the oil reservoir of the engine, the lubricity of the oil can be degraded sufficiently to adversely affect the wear of various sliding engine parts. It would therefore be significantly beneficial if an oil storage and collection system of a tilted in-line marine engine could be provided with an arrangement that decreases the aeration of oil stored within the lubrication system while also decreasing the adverse efficiency effect caused by a mist of oil vapor and droplets in the vicinity of rotating components of the engine, such as the crankshaft, connecting rods, and counterweights.